Deming on Software: Bugs 1

Deming wrote:

Everyone in your company knows that the aim is perfection, that you can not tolerate defectives and mistakes. You make every worker responsible for the defectives that he has produced. Yet from the records that you have showed to me, it is obvious that you are tolerating a high proportion of defectives, and have been doing so for years. In fact, the levels of various kinds of mistake have not decreased; they have been pretty constant and predictable over a a number of years.

Have you any reason to think that the level of mistakes will decrease in the future? Have you ever thought that the problem could be in the system?